Many fruits and vegetables contain an array of phytochemicals that contribute to good health. Epidemiological, clinical, and laboratory studies suggest that various carotenoids reduce the onset of chronic diseases, including coronary heart disease (Barton-Duell (1995) Endocrinologist 5:347-356), certain cancers (Giovannucci (1999) J. Natl. Cancer Inst., 91:317-331), and age-related macular degeneration (Seddon et al. (1994) J. Am. J. Med. Assoc., 272:1413-1420). Thus, modulation of carotenoid biosynthesis in plants by genetic manipulation should affect the nutritional quality of the crop.
Pineapple plants (Ananas comosus of the Bromeliaceae family) are tropical monocotyledonous plants that have rigid spiny-margined recurved leaves and short stalks with dense oblong heads of small abortive flowers. The fruit of many varieties of pineapple plants is used for human consumption. Some of these varieties include Smooth Cayenne, Red Spanish, Perolera, Pernambuco, and Primavera. The plant is self-incompatible, with long periods between successive fruit generations. As a consequence, conventional breeding to improve fruit quality and other agronomic traits has been difficult.
From the foregoing discussion, it is apparent that transgenic pineapple plants with modified carotenoid levels are desirable. In particular, pineapple plants having elevated carotenoid levels in fruit tissues would enhance the nutritional quality of this important crop. Further, genetically transformed pineapple plants having altered coloration are desirable, inter alia, for product differentiation. These and a variety of other features of the present invention will become evident upon complete review of the following disclosure.